U.S. Pat. No. 3,428,526 describes the production of monorden and states that monorden possesses a strong inhibiting effect on the increase of tumor cells of the mouse Mastocytoma p. 815 in vitro. Preparation of monorden is also described by McCapra et al, Tetrahedron Letters, 869-875 (1964) and by Mirrington et al (Tetrahedron Letters, 365-370 (1964)). Mirrington et al also describes the conversion of monorden to dimethoxy monorden by reaction with potassium carbonate/methyl iodide.